Of uncertain, risky outcome.
Fraught with danger.
Nauseating, rank.
Of doubtful or uncertain efficacy, provenance, etc.; dodgy.
Not settled, uncertain, of uncertain outcome; debatable, questionable, open to doubt.
Difficult to overcome, solve, or decide.
Contributing (especially if subtly) to discrimination (such as racism, sexism, homophobia, transphobia, or ageism).
a problematic analysis
A problem or difficulty in a particular field of study.